Spring.



No.'633,328. Patented Sept. I9', |899. F. E. ROBERTS.

S P R I N G.

(Application led Mar. 1, 189 9.)

(No Model.)

INVENTOR.

WITNESSES: V I I Wax TH: Nonms mins co. Puoommo. wAsmNt-TON, n, c.

. UNITED STATESv PATENT OFFICE.

i FRANK E. ROBERTS, OF TOLEDO, OHIO, ASSIGNOR OF ONE-HALF TO MARY F.MUNSON, OF SAME PLACE.

SPRING.

SPECIFICATION forming part of Letters Patent No. 633,328, datedSeptember 19, 1399.

I Application tiled ylVIarcll l, 1899. Serial No. 707,292. (No model.)

T all whom, t muy concern.'

Be it known that I, FRANK E. ROBERTS, a citizen of the UnitedStates,residing at Toledo, Lucas county, Ohio, have invent-ed certainnew and useful Improvements in Springs, of

which the following is a specification.

My invention relates to a compound helical spring for spring-motors; andits object is to provide a spring which in a minimum of space shall havea maximum of capacity and of time limit in its unwinding.

To this end my invention consists in the construction and arrangementshown and illustrated in `the accompanying drawings, x5 made parthereof, and described in the following specification.

In said drawings, Figure 1 isa side elevation of my spring with portionsbrokenv away to show several of the layers hereinafter referred to, andFig. 2 is an end view of the vsame with one end of the frame removed.

In the draWings,.A is a frame or housing having journaled therein ashaft b, provided with suitable means for imparting motion tothemechanism to be driven, such as a pinion c.

(Z is a spring secured at one end to a fixed point, as at e, and at theother end to the shaft to be driven, as atf. This spring consists of along strip of suitable metal, such as spring-steel, and is spirallywound the desired distance along the shaft from its point of fastening.The strip is next Wound in the opposite direction upon the first helixthus formed to or near to the starting-point. Now the winding continuesupon the second helix a suitable distance in the same direction as thewinding of the Iirst, and so on, one helix being superimposed uponanother until the desired number ofcoils is formed. of the outer coil isnow secured to some fixed point, as at e. In the example of my deviceillustrated in the drawings there are shown seven concentric coils,numbered progres- 45 sively outwardly from l to 7. The shaft being:revolved in a direction opposite to the windings of the spring, thefirst layer is compressed upon or near to its shaft. The rotation of theshaft being continued, the second 5o helix is wound upon and caused toembrace The end the first helix. The winding being continued, the thirdhelix is caused to embrace the second helix, and so on until thesucceeding helices are progressively compressed into working position.Now the shaft being released, the outer helix 7 will first by itsresiliency unwind itself and expend its energy, the next succeedinghelix being held against operation until its incasing coil issuiiiciently expanded to release the first winding of the nextsucceeding coil G. This coil now proceeds to unwind itself in the samemanner as did coil 7 until its clasp upon the vnext inner coil 5 isreleased. ln this manner coil after coil is released and thrown intooperation by the unwindingv of the outer inclosing coils until finallythe inner helix is permitted to unwind itself. As coil after coilunwinds itself n10- tion is imparted to the shaft and to its connectedgear.

It will be seen that from a single piece of metal I have constructed aspring which ap proximately from the beginning to the end of itsoperation delivers to its shaft a uniform thrust or pull, that theseveral sections of the same spring operate successively, that the spaceoccupied by the spring is small, and that the unwinding of the severalsuperim posed sections or layers will consume a con siderable period oftime.

The shaft may after the spring is wound up be rigidly secured againstrotation, and the housing may be revolubly mounted upon the shaft andconnect-ed with adriving mechanism with substantially the same result aswith the arrangement above described witha out departing from myinvention.

Having described my invention, what I claim, and desire to secure byLetters Patent, 1s-

A spring, comprising a strip of metal, spirally wound in a plurality ofconcentric layi ers or helices, one layer or series of windings beingsuperimposed upon another, substam tially as described.

FRANK E. ROBERTS.

In presence ofi F. M. DoTsoN, L. E. BROWN.

